swift - 如何在swift中通过web api将图像保存到数据库表

Question

我正在使用 Swift 3.0 构建一个应用程序用于学习目的。其中一项功能是从 SQL Server 数据库表中获取数据并将其保存到其中。其中一列是在表中存储IMAGE(照片):表中的数据类型是SQL Server中的Image(system.Byte[])。

我可以通过 Web api 获取照片列并将其显示在图像组件中，如下所示:

let encodedImageData = My web api url
let imageData = NSData(base64EncodedString: encodedImageData   options: .allZeros)
let image = UIImage(data: imageData)
let imageView.image = image

我在通过 Web api 将图像保存到数据库时遇到问题(可以保存其他列，但图像列有问题)。我试过这个:

let data = UIImagePNGRepresentation(image) as NSData?

但是失败了。

我的网络 API 和调用如下:

func post(parameters : Dictionary<String, String>, urlString : String) {


    var request = URLRequest(url: URL(string: urlString)!)
    let session = URLSession.shared
    request.httpMethod = "POST"
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    request.httpBody = try! JSONSerialization.data(withJSONObject: parameters)

    let task = session.dataTask(with: request) { data, response, error in
        guard let data = data, error == nil else {
            print("error: \(error)")
            return
        }

        do {
            if let json = try JSONSerialization.jsonObject(with: data) as? [String: Any] {
                let success = json["success"] as? Int                                  // Okay, the `json` is here, let's get the value for 'success' out of it
                print("Success: \(success)")
            } else {
                let jsonStr = String(data: data, encoding: .utf8)    // No error thrown, but not dictionary
                print("Error could not parse JSON: \(jsonStr)")
            }
        } catch let parseError {
            print(parseError)                                                          // Log the error thrown by `JSONObjectWithData`
            let jsonStr = String(data: data, encoding: .utf8)
            print("Error could not parse JSON: '\(jsonStr)'")
        }
    }

    task.resume()


}

@IBAction func insert(){

 let imageData = UIImagePNGRepresentation(myimageview.image!) as NSData?

 post(parameters: ["Name": nametxt.text!,"Address": addresstxt.text!,"photoname": photonametxt.text!,"photo": String(describing: imageData),"url": urltxt.text! ], urlString: "http://XXXXXXX/api/myfavorites")

}

有人可以帮我看看 Swift 中图像保存到数据库表的方法吗？

Answer 1

我认为您的图像使用了错误的数据结构。您应该直接使用 base64 编码的字符串，而不是使用 NSData 和 String(describing:) (这绝对不会达到您想要的效果) ，如下面的代码:

@IBAction func insert(){

    let imageBase64String = UIImagePNGRepresentation(myimageview.image!)?.base64EncodedString()

    post(parameters: ["Name": nametxt.text!,"Address": addresstxt.text!,"photoname": photonametxt.text!,"photo": imageBase64String,"url": urltxt.text! ], urlString: "http://XXXXXXX/api/myfavorites")

}